aesio: add basic AES encryption and decryption

This adds initial support for an AES module named aesio.  This
implementation supports only a subset of AES modes, namely
ECB, CBC, and CTR modes.

Example usage:

```
>>> import aesio
>>>
>>> key = b'Sixteen byte key'
>>> cipher = aesio.AES(key, aesio.MODE_ECB)
>>> output = bytearray(16)
>>> cipher.encrypt_into(b'Circuit Python!!', output)
>>> output
bytearray(b'E\x14\x85\x18\x9a\x9c\r\x95>\xa7kV\xa2`\x8b\n')
>>>
```

This key is 16-bytes, so it uses AES128.  If your key is 24- or 32-
bytes long, it will switch to AES192 or AES256 respectively.

This has been tested with many of the official NIST test vectors,
such as those used in `pycryptodome` at
https://github.com/Legrandin/pycryptodome/tree/39626a5b01ce5c1cf51d022be166ad0aea722177/lib/Crypto/SelfTest/Cipher/test_vectors/AES

CTR has not been tested as NIST does not provide test vectors for it.

Signed-off-by: Sean Cross <sean@xobs.io>

1 files changed, 53 insertions, 0 deletions

diff --git a/shared-bindings/aesio/__init__.h b/shared-bindings/aesio/__init__.h
new file mode 100644
index 000000000..634fed2e5
--- /dev/null
+++ b/shared-bindings/aesio/__init__.h
@@ -0,0 +1,53 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MICROPY_INCLUDED_SHARED_BINDINGS_AESIO_H
+#define MICROPY_INCLUDED_SHARED_BINDINGS_AESIO_H
+
+#include "shared-module/aesio/__init__.h"
+
+extern const mp_obj_type_t aesio_aes_type;
+
+void common_hal_aesio_aes_construct(aesio_aes_obj_t* self,
+                              const uint8_t* key,
+                              uint32_t key_length,
+                              const uint8_t* iv,
+                              int mode,
+                              int counter);
+void common_hal_aesio_aes_rekey(aesio_aes_obj_t* self,
+                          const uint8_t* key,
+                          uint32_t key_length,
+                          const uint8_t* iv);
+void common_hal_aesio_aes_set_mode(aesio_aes_obj_t* self,
+                             int mode);
+void common_hal_aesio_aes_encrypt(aesio_aes_obj_t* self,
+                            uint8_t* buffer,
+                            size_t len);
+void common_hal_aesio_aes_decrypt(aesio_aes_obj_t* self,
+                            uint8_t* buffer,
+                            size_t len);
+
+#endif // MICROPY_INCLUDED_SHARED_BINDINGS_AESIO_H